1. Field of the Invention
The present invention is generally related to Glycosaminoglycanase enzymes, including Neutral-Active, Soluble Hyaluronidase Glycoproteins (sHASEGPs), and portions thereof, particularly Hyaluronidase domains. More specifically, the invention is related to chemical modifications, pharmaceutical compositions, expression plasmids, methods for manufacture and therapeutic methods using the Glycosaminoglycanases (and domains thereof and the encoding nucleic acid molecules) for the therapeutic modification of glycosaminoglycans in the treatment of disease and for use to increase diffusion of other molecules such as injected molecules in an animal.
2. Background Information
Glycosaminoglycans (GAGs) are complex linear polysaccharides of the extracellular matrix (ECM). GAGs are characterized by repeating disaccharide structures of an N-substituted hexosamine and an uronic acid, (in the case of hyaluronan (HA), chondroitin sulfate (CS), chondroitin (C), dermatan sulfate (DS), heparan sulfate (HS), and heparin (H)), or a galactose, (in the case of keratan sulfate (KS)). Except for HA, all exist covalently bound to core proteins. The GAGs with their core proteins are structurally referred to as proteoglycans (PGs).
Hyaluronan (HA) is found in mammals predominantly in connective tissues, skin, cartilage, and in synovial fluid. Hyaluronan is also the main constituent of the vitreous of the eye. In connective tissue, the water of hydration associated with hyaluronan creates hydrated matrices between tissues. Hyaluronan plays a key role in biological phenomena associated with cell motility including rapid development, regeneration, repair, embryogenesis, embryological development, wound healing, angiogenesis, and tumorigenesis (Toole 1991 Cell Biol. Extracell. Matrix, Hay (ed), Plenum Press, New York, 305-341; Bertrand et al. 1992 Int. J. Cancer 52:1-6; Knudson et al., 1993 FASEB J. 7:1233-1241). In addition, hyaluronan levels correlate with tumor aggressiveness (Ozello et al. 1960 Cancer Res. 20:600-604; Takeuchi et al. 1976, Cancer Res. 36:2133-2139; Kimata et al. 1983 Cancer Res. 43:1347-1354).
HA is found in the extracellular matrix of many cells, especially in soft connective tissues. HA has been assigned various physiological functions, such as in water and plasma protein homeostasis (Laurent T C et al (1992) FASEB J 6: 2397-2404). HA production increases in proliferating cells and may play a role in mitosis. It has also been implicated in locomotion and cell migration. HA seems to play important roles in cell regulation, development, and differentiation (Laurent et al., supra).
HA has been used in clinical medicine. Its tissue protective and rheological properties have proved useful in ophthalmic surgery (e.g. to protect the corneal endothelium during cataract surgery). Serum HA is diagnostic of liver disease and various inflammatory conditions, such as rheumatoid arthritis. Interstitial edema caused by accumulation of HA may cause dysfunction in various organs (Laurent et al., supra).
Hyaluronan protein interactions also are involved in the structure of the extracellular matrix or “ground substance”.
Hyaluronidases are a group of generally neutral- or acid-active enzymes found throughout the animal kingdom. Hyaluronidases vary with respect to substrate specificity, and mechanism of action.
There are three general classes of hyaluronidases:
1. Mammalian-type hyaluronidases, (EC 3.2.1.35) which are endo-beta-N-acetylhexosaminidases with tetrasaccharides and hexasaccharides as the major end products. They have both hydrolytic and transglycosidase activities, and can degrade hyaluronan and chondroitin sulfates (CS), generally C4-S and C6-S.
2. Bacterial hyaluronidases (EC 4.2.99.1) degrade hyaluronan and, and to various extents, CS and DS. They are endo-beta-N-acetylhexosaminidases that operate by a beta elimination reaction that yields primarily disaccharide end products.
3. Hyaluronidases (EC 3.2.1.36) from leeches, other parasites, and crustaceans are endo-beta-glucuronidases that generate tetrasaccharide and hexasaccharide end products through hydrolysis of the beta 1-3 linkage.
Mammalian hyaluronidases can be further divided into two groups: neutral-active and acid-active enzymes. There are six hyaluronidase-like genes in the human genome, HYAL1, HYAL2, HYAL3 HYAL4 HYALP1 and PH20/SPAM1. HYALP1 is a pseudogene, and HYAL3 has not been shown to possess enzyme activity toward any known substrates. HYAL4 is a chondroitinase and exhibits little activity towards hyaluronan. HYAL1 is the prototypical acid-active enzyme and PH20 is the prototypical neutral-active enzyme. Acid active hyaluronidases, such as HYAL1 and HYAL2 generally lack catalytic activity at neutral pH (i.e. pH 7). For example, HYAL1 has little catalytic activity in vitro over pH 4.5 (Frost et al Anal Biochemistry, 1997). HYAL2 is an acid-active enzyme with a very low specific activity in vitro.
The hyaluronidase-like enzymes can also be characterized by those which are generally locked to the plasma membrane via a glycosylphosphatidyl inositol anchor such as human HYAL2 and human PH20 (Danilkovitch-Miagkova et al., Proc Natl Acad Sci USA. 2003 Apr. 15; 100(8):4580-5, Phelps et al., Science 1988), and those which are generally soluble such as human HYAL1 (Frost et al., Biochem Biophys Res Commun. 1997 Jul. 9; 236(1):10-5). However, there are variations from species to species: bovine, PH20 for example is very loosely attached to the plasma membrane and is not anchored via a phospholipase sensitive anchor (Lalancette et al., Biol Reprod. 2001 August; 65(2):628-36.). This unique feature of bovine hyaluronidase has permitted the use of the soluble bovine testes hyaluronidase enzyme as an extract for clinical use (Wydase™, Hyalase™). Other PH20 species are lipid anchored enzymes that are generally not soluble without the use of detergents or lipases. For example, human PH20 is anchored to the plasma membrane via a GPI anchor. Attempts to make human PH20 DNA constructs that would not introduce a lipid anchor into the polypeptide resulted in either a catalytically inactive enzyme, or an insoluble enzyme (Arming et al Eur J. Biochem. 1997 Aug. 1; 247(3):810-4). Naturally occurring macaque sperm hyaluronidase is found in both a soluble and membrane bound form. While the 64 kDa membrane bound form possesses enzyme activity at pH 7.0, the 54 kDa form is only active at pH 4.0 (Chen et al., Dev Biol. 1996 Apr. 10; 175(1):142-53.). Thus, soluble forms of PH20 are often lacking enzyme activity under neutral conditions.
Chondroitinases are enzymes found throughout the animal kingdom. These enzymes degrade glycosaminoglycans through an endoglycosidase reaction. Specific examples of known Chondroitinases include Chondroitinase ABC (derived from Proteus vulgaris; Japanese Patent Application Laid-open No 6-153947, T. Yamagata, H. Saito, O. Habuchi, and S. Suzuki, J. Biol. Chem., 243, 1523 (1968), S. Suzuki, H. Saito, T. Yamagata, K. Anno, N. Seno, Y. Kawai, and T. Furuhashi, J. Biol. Chem., 243, 1543 (1968)); Chondroitinase AC (derived from Flavobacterium heparinum; T. Yamagata, H. Saito, O. Habuchi, and S. Suzuki, J. Biol. Chem., 243, 1523 (1968)); Chondroitinase AC II (derived from Arthrobacter aurescens; K. Hiyama, and S. Okada, J. Biol. Chem., 250, 1824 (1975), K. Hiyama and S. Okada, J. Biochem. (Tokyo), 80, 1201 (1976)); Hyaluronidase ACM (derived from Flavobacterium sp. Hp102; Hirofumi Miyazono, Hiroshi Kikuchi, Keiichi Yoshida, Kiyoshi Morikawa, and Kiyochika Tokuyasu, Seikagaku, 61, 1023 (1989)); Chondroitinase B (derived from Flavobacterium heparinum; Y. M. Michelacci and C. P. Dietrich, Biochem. Biophys. Res. Commun., 56, 973 (1974), Y. M. Michelacci and C. P. Dietrich, Biochem. J., 151, 121 (1975), Kenichi Maeyama, Akira Tawada, Akiko Ueno, and Keiichi Yoshida, Seikagaku, 57, 1189 (1985)); Chondroitinase C (derived from Flavobacterium sp. Hp102; Hirofumi Miyazono, Hiroshi Kikuchi, Kelichi Yoshida, Kiyoshi Morikawa, and Kiyochika Tokuyasu, Seikagaku, 61, 1023 (1989)); and the like.
Glycoproteins are composed of a polypeptide chain covalently bound to one or more carbohydrate moieties. There are two broad categories of glycoproteins that possess carbohydrates coupled though either N-glycosidic or O-glycosidic linkages to their constituent protein. The N- and O-linked glycans are attached to polypeptides through asparagine-N-acetyl-D-glucosamine and serine (threonine)-N-acetyl-D-galactosamine linkages, respectively. Complex N-linked oligosaccharides do not contain terminal mannose residues. They contain only terminal N-acetylglucosamine, galactose, and/or sialic acid residues. Hybrid oligosaccharides contain terminal mannose residues as well as terminal N-acetylglucosamine, galactose, and/or sialic acid residues.
With N-linked glycoproteins, an oligosaccharide precursor is attached to the amino group of asparagine during peptide synthesis in the endoplasmic reticulum. The oligosaccharide moiety is then sequentially processed by a series of specific enzymes that delete and add sugar moieties. The processing occurs in the endoplasmic reticulum and continues with passage through the cis-, medial- and trans-Golgi apparatus.